[PATCH] pread/pwrite: handle targets that align 64bit values in register pairs
Justin Maggard
jmaggard10 at gmail.com
Wed Feb 5 00:43:30 UTC 2014
Recent changes to pread/pwrite in the 0.9.33 branch to use the proper
linux kernel syscalls failed to consider architectures that align 64-bit
values in register pairs. These targets are already marked because
their truncate64 syscall required a different number of args as well.
Use the existing __UCLIBC_TRUNCATE64_HAS_4_ARGS__ definition to also
determine whether we should use 5 or 6 args for pread/pwrite.
---
libc/sysdeps/linux/common/pread_write.c | 51 +++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
diff --git a/libc/sysdeps/linux/common/pread_write.c b/libc/sysdeps/linux/common/pread_write.c
index b13de66..b8d527b 100644
--- a/libc/sysdeps/linux/common/pread_write.c
+++ b/libc/sysdeps/linux/common/pread_write.c
@@ -43,6 +43,19 @@ extern __typeof(pwrite64) __libc_pwrite64;
#include <bits/kernel_types.h>
# define __NR___syscall_pread __NR_pread64
+# ifdef __UCLIBC_TRUNCATE64_HAS_4_ARGS__
+static __inline__ _syscall6(ssize_t, __syscall_pread, int, fd, void *, buf,
+ size_t, count, int, dummy, off_t, offset_hi, off_t, offset_lo)
+
+ssize_t __libc_pread(int fd, void *buf, size_t count, off_t offset)
+{
+ int oldtype = LIBC_CANCEL_ASYNC ();
+ int result = __syscall_pread(fd, buf, count, 0, __LONG_LONG_PAIR(offset >> 31, offset));
+ LIBC_CANCEL_RESET (oldtype);
+ return result;
+
+}
+# else
static __inline__ _syscall5(ssize_t, __syscall_pread, int, fd, void *, buf,
size_t, count, off_t, offset_hi, off_t, offset_lo)
@@ -54,9 +67,21 @@ ssize_t __libc_pread(int fd, void *buf, size_t count, off_t offset)
return result;
}
+# endif
weak_alias(__libc_pread,pread)
# ifdef __UCLIBC_HAS_LFS__
+# ifdef __UCLIBC_TRUNCATE64_HAS_4_ARGS__
+ssize_t __libc_pread64(int fd, void *buf, size_t count, off64_t offset)
+{
+ uint32_t low = offset & 0xffffffff;
+ uint32_t high = offset >> 32;
+ int oldtype = LIBC_CANCEL_ASYNC ();
+ int result = __syscall_pread(fd, buf, count, 0, __LONG_LONG_PAIR(high, low));
+ LIBC_CANCEL_RESET (oldtype);
+ return result;
+}
+# else
ssize_t __libc_pread64(int fd, void *buf, size_t count, off64_t offset)
{
uint32_t low = offset & 0xffffffff;
@@ -66,6 +91,7 @@ ssize_t __libc_pread64(int fd, void *buf, size_t count, off64_t offset)
LIBC_CANCEL_RESET (oldtype);
return result;
}
+# endif
weak_alias(__libc_pread64,pread64)
# endif /* __UCLIBC_HAS_LFS__ */
@@ -75,6 +101,18 @@ weak_alias(__libc_pread64,pread64)
#endif
# define __NR___syscall_pwrite __NR_pwrite
+# ifdef __UCLIBC_TRUNCATE64_HAS_4_ARGS__
+static __inline__ _syscall6(ssize_t, __syscall_pwrite, int, fd, const void *, buf,
+ size_t, count, int, dummy, off_t, offset_hi, off_t, offset_lo)
+
+ssize_t __libc_pwrite(int fd, const void *buf, size_t count, off_t offset)
+{
+ int oldtype = LIBC_CANCEL_ASYNC ();
+ int result = __syscall_pwrite(fd, buf, count, 0, __LONG_LONG_PAIR(offset >> 31, offset));
+ LIBC_CANCEL_RESET (oldtype);
+ return result;
+}
+# else
static __inline__ _syscall5(ssize_t, __syscall_pwrite, int, fd, const void *, buf,
size_t, count, off_t, offset_hi, off_t, offset_lo)
@@ -85,9 +123,21 @@ ssize_t __libc_pwrite(int fd, const void *buf, size_t count, off_t offset)
LIBC_CANCEL_RESET (oldtype);
return result;
}
+# endif
weak_alias(__libc_pwrite,pwrite)
# ifdef __UCLIBC_HAS_LFS__
+# ifdef __UCLIBC_TRUNCATE64_HAS_4_ARGS__
+ssize_t __libc_pwrite64(int fd, const void *buf, size_t count, off64_t offset)
+{
+ uint32_t low = offset & 0xffffffff;
+ uint32_t high = offset >> 32;
+ int oldtype = LIBC_CANCEL_ASYNC ();
+ int result = __syscall_pwrite(fd, buf, count, 0, __LONG_LONG_PAIR(high, low));
+ LIBC_CANCEL_RESET (oldtype);
+ return result;
+}
+# else
ssize_t __libc_pwrite64(int fd, const void *buf, size_t count, off64_t offset)
{
uint32_t low = offset & 0xffffffff;
@@ -97,5 +147,6 @@ ssize_t __libc_pwrite64(int fd, const void *buf, size_t count, off64_t offset)
LIBC_CANCEL_RESET (oldtype);
return result;
}
+# endif
weak_alias(__libc_pwrite64,pwrite64)
# endif /* __UCLIBC_HAS_LFS__ */
--
1.7.9.5
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